<!DOCTYPE html>
<html>
<head>
  <meta charset="UTF-8">
  <title>Document</title>
  <style></style>
</head>
<div>
  <div>aaaaa</div>
</div>
<body>
 
</body>
 <script>
    // 方式1
    
    window.onload = function () {
      
      
    
    };
 
  </script>
</html>